UDP provides two services not provided by the IP layer. It provides port numbers to help distinguish different user requests and, optionally, a checksum capability to verify that the data arrived intact.
TCP has emerged as the dominant protocol used for the bulk of internet connectivity due to its ability to break large data sets into individual packets, check for and resend lost packets, and reassemble packets in the correct sequence. But these additional services come at a cost in terms of additional data overhead and latency.
TCP and UDP are part of the TCP/IP protocol suite, which includes a number of protocols for carrying out network communications.

A chart displaying the differences between UDP and TCP

UDP characteristics include the following:
● It is a connectionless protocol.
● It is used for VoIP, video streaming, gaming and live broadcasts.
● It is faster and needs fewer resources.
● The packets don't necessarily arrive in order.
● It allows missing packets -- the sender is unable to know whether a packet has been received.
● It is better suited for applications that need fast, efficient transmission, such as games.

TCP characteristics include the following:

● It is a connection-oriented protocol.
● It's the most widely used protocol on the internet.
● It guarantees that no packets are missing and all the data that's sent makes it to the intended recipient.
● It sends packets in order so they can be stitched back together easily.
● It's slower and requires more resources.
● It has a bigger header than UDP.

● It is best suited for apps that need high reliability, and transmission time is relatively less critical.